Depends on what your hire conditions are. For example, with Sixt in Germany the default is that only third party insurance is included - I am responsible for any damage to the car, up to the full value. A basic loss damage waiver up to 1000 Euros (which is normally included as standard for UK hires) has to be bought extra. I then take out further insurance via a company such as Insurance4carhire to cover me for the excess.